This invention relates to a process for the production of [1,1-dithien-(3)-yl-1-hydroxy-(3)-propyl]-[1-phenyl-1-hydroxy-(2)-propyl]- amine and [1,1-dithien-(3)-yl-(1)-propen-(3)-yl]-[1-phenyl-(2)-propyl]-amine.
It is known that [1,1-dithien-(3)-yl-1-hydroxy-(3)-propyl]-[1-phenyl-1-hydroxy-(2)-propyl]- amine corresponding to the formula ##STR3## can be reproduced using thien-(3)-yl lithium (Thiele German Patent Specification No. 1,921,453): ##STR4##
The tertiary hydroxy group in compound I can be split off by treatment with dehydrating agents to form [1,1-dithien-(3)-yl-(1)-propen-(3)-yl]-[1-phenyl-(2)-propyl]-amine.
The compound of formula (I) has valuable pharmacodynamic properties. In addition, it is an important intermediate product for the production of [1,1-dithien-(2)-yl-(1)-propen-(3)-yl]-[1-phenyl-1-hydroxy-(2)-propyl]-ami ne which also shows considerable pharmacodynamic activity.
Unfortunately, the known methods A and B are attended by serious disadvantages which prevent compound I from being produced on a commercial scale.
Thus, in the known processes, the reaction is not uniform and the required compound of formula (I) can only be isolated in maximum yields of 30%. In particular, thien-(2)-yl isomers are formed in fairly large quantities in these processes.
In addition, separation of the required compound I from the other reaction products and its purification are extremely difficult and can only be carried out for example by elaborate and complicated recrystallisation several times in combination with treatment with active carbon. Thus, in conventional processes, the [1,1-dithien-(3)-yl-1-hydroxy-(3)-propyl]-[1-phenyl-1-hydroxy-(2)-propyl]- amine of formula (I) is obtained in a yield of only about 27% (method A) or in a yield of only about 24% (method B), cf. the two Comparison Examples.